In what experts are calling a “crisis in crop pollination,” farmers worldwide are contending with rapidly dwindling bee populations; U.S. honey bee colony counts have decreased by an estimated 50 percent since the 1950’s. Not only does the decline affect the livelihood of farmers, it poses a threat to food crops across the globe as bees provide a critical function to ecosystems by cross-pollinating, or re-distributing pollen amongst male and female plants. Without bees to spread the pollen, many crops cannot yield fruit.

With a $3.3 million grant from the U.S. Department of Agriculture, UMass Amherst Associate Professor of Entomology Anne Averill and colleagues are studying the decline of various bee species and will generate recommendations to address the problem. Averill, who specializes in cranberry bog habitats and entomology, oversees a team of researchers within the University and across the Northeast. Associate Professor of Entomology John Burand works with Averill to analyze the scientific samples the team collects and to test insect samples for pathogens; Thomas Stevens, Professor of Resource Economics provides a socioeconomic perspective to address grower habits; and Dr. Guang Xu in the Genomics Resource Lab and Department of Plant, Soil, and Insect Sciences uses genetic sequencing to discover new pathogens in the bee communities. The team is also collaborating with scientists from Cornell University, the Connecticut Agricultural Experiment Station, University of Maine, and the University of Tennessee.

The research team is using Northeastern specialty crops cranberry, lowbush blueberry, apple and cucurbits (pumpkins and squash) as a base for the five-year study. The project focuses on native bees, which Averill explains are bees that inhabited North America before Europeans introduced honeybees to the continent in the 1600’s. According to Averill, native bee species are underutilized pollinators. Much of the concern that has plagued agricultural communities for the past decade surrounds honey bee populations. Every spring, many farmers enlist the help of managed honey bee colonies to pollinate their crops, yet the service is becoming increasingly costly as managed bee availability is decreasing. While it remains unclear whether or not native bees are declining in a similar fashion, Averill has concluded that at least three bumble bee species have disappeared within the last twenty years.

“It’s kind of distressing that we’re backing ourselves into a situation where we have fewer and fewer pollinators,” says Averill.

The team is in the investigation stage of the project, which requires considerable time behind a microscope. The collaborators are collecting samples from participating farms and analyzing the findings. The analysis has a gut-pathogen and insecticide component. In order to test how the bee is affected internally, the lower abdomen is removed and the gut is extracted and tested for various afflictions that could be contributing to a decline. The DNA and RNA are also removed for genetic sequencing to determine presence of both known and yet-to-be discovered pathogens.

Because of the rampant decline, Averill hypothesizes that the team will find pollen deficits (lack of sufficient pollen transfer to flowers) in every farm they visit. This does not bode well for farmers or their crops; pollen deficits tend to reduce crop yield. Studies have shown that the more pollination a crop receives, the more seeds are present in fruit produced and the larger the fruit grow. Since grower education is an integral part of the project, Averill and the team are compiling materials for the “pollination toolbox,” a collection of data and strategies that will help farmers to determine the adequacy of pollination on their farms and to sustain efficient and diverse pollinator habitats.

“A good, secure pollination community could be critical for the success of those industries,” adds Averill.

Averill says that identifying the different bee species (which number in the hundreds) is time intensive because they are often differentiated by mere minute details. Mapping the native species is important as there is no historical data to reference. Averill’s research indicates an abundance of wild bee populations on Cape Cod, that many of these species are better at pollinating as honey bees, and that many bog farmers may not have to bring in honey bees if they can encourage these native species.

Averill hypothesizes that the more diverse the habitat, the more conducive it is to supporting wild bees. Since many farms are frequently mowed monocultures, they are often not supportive of native bee colonies. Averill explains that while honeybees are rented for the short period of time they are needed for early season pollination, native bees do not get packed up and transported to other locations; they need food and nesting sites throughout the season. The research team advises farmers to leave unmanaged areas rich with wildflowers, twigs and underground thatches. Farmers also tend to get rid of pesky rodents, yet vacant rodent tunnels are a favored nesting place for bees. If a bumble bee queen is unable to find early season wildflowers or suitable nesting conditions, she will bumble elsewhere to build her colony, and the farm loses an important source of pollination.

Averill advises farmers that a diverse pollination method, using both managed honeybee colonies and native bees, is more in keeping with sustainable pollination practices. Not only can farmers save money by taking in fewer honey bees, but they can also ensure their crops are better pollinated. Averill explains that not all bee species function equally, that to depend on any one species to pollinate a crop is overall less secure.

“People in ecology know: the more different species that you have, the more stable the ecosystems,” Averill says.

Unique to the project is the inclusion of a socioeconomic backdrop. The team can make stronger recommendations by identifying “road blocks” and cost-effective strategies for struggling farmers who depend on annual production.

“It’s a pretty exciting time. I think we can have some major impacts,” says Averill.

Amanda Drane ‘12

U.S. honey bee colony counts have decreased by an estimated 50 percent since the 1950’s